The present invention relates to the field of cable retainers and, in particular, to the use of such retainers in aircraft engine cabling.
Airplane engines which are wing-mounted are rigidly attached to a strut which is itself mounted to a wing. FIG. 1 shows an airplane engine 1 mounted to wing 2 via strut 3. Airplane engines are also mechanically coupled to alternators or generators which convert the engines' mechanical energy into electrical power, typically 3-phase, 400 Hz, which is supplied to the airplane avionics and other electrical subsystems. FIG. 1 shows in phantom line an alternator 4 coupled to provide such electrical power. Cabling, such as cable set 5, runs from the alternator 4 to the body of the airplane to carry the electrical power. Such cabling generally includes, for each phase, two conductors, typically #1/0 wire, or a total of six conductors for a conventional engine. The conductors in such cables usually pass through a connector, such as connector 6 in FIG. 1, one portion of which is rigidly mounted in the rear bulkhead of the strut. Additional cabling running from the other side of the bulkhead to the body of the airplane is connected to the mounted portion of the connector.
The standard connector, which is called an MS connector, can accommodate 4-6 conductors. Each portion of such a connector contains either pins or sockets molded to the connector. Such connectors are typically three (3) inches in diameter and can withstand 6000 pounds of tension.
Although the strength of such connectors must be great to withstand the airplane environment, occasionally the connector's strength causes problems. The loss of an airplane engine during flight due to failure of a strut holding that engine will not usually cause the airplane to crash. The remaining engines can normally provide sufficient power for flight. In the past, a more significant problem caused by a broken strut is the destruction of the wing by an engine which has not separated from the broken strut. What happens is that the engine remains tethered to the wing by the six or more power conductors and connector. Since the cable and the associated conductors are very strong, as is the connection at the MS connector, the engine does not drop freely, but instead swings around and damages the wing.
An additional problem with MS connectors is their size. The aircraft industry is moving toward the use of larger engines. In order to preserve conventional ground clearance while using such larger engines, airplane manufacturers have chosen to reduce the size of the struts. The MS connectors may be found to be too large to be mounted on the rear strut bulkheads of these smaller struts.